In his latest post Brandon Savage asks you, the Composer users out there, if you know exactly what's in your "composer.json" file. If you're not a Composer user already, he also introduces you to the tool and what it can do for you and your applications.

During the recent Crafting Code Tour, Paul Jones would ask people who was currently using Composer. It was a rare night that more than half an audience raised their hands, meaning that the best invention in the PHP world in the last three years is still not being widely used by everybody. I want to share a bit about how to get started with Composer, and why you should care in the first place.

He starts with the brief overview of what Composer is and how it works with the configuration file to pull in packages and make them available via autoloading. He shows how to download and install the tool and includes a simple "composer.json" file that installs the Monolog package. He also includes his own answer to the "what's in your file" question, showing a more advanced configuration requiring several packages and defining custom autoloading and executable directories.